Extraction apparatus and method



May 5, 1942- l.. c. swALLx-:N' ETAL 2,282,265'y l EXTRACTION APPARATUSAND METHOD May 5, 1942. L. c. swALLEN ET A1.

EXTRACTION APPARATUS AND METHOD Filed Aug. 17, 1959 sheets-she'et 2 dljgyd 15u/allen Patented May 5, 1942 UNITED STATES PATENT OFFICEEXTRACTION APPARATUS AND METHOD- 4 Lloyd C. Swallen, Argo, and HaroldReintjes.

Berwyn, lll., asslgnors to Corn Products I te- York, N. Y., acorporation inlng Company, New

of New Jersey Application August 17, 1939, serial No. 290,606

3 Claims.

which material is solid and relatively dense so that it will be capableof settling readily in the solution.

A further object of the invention is to provide an extraction apparatuswhich will be simple and economical in respect to its construction andoperation; which will be capable of being conveniently regulated toproduce a clear solution containing a maximum quantity of solubles; andwhich can be easily kept clean.

The process of extraction provided by this invention is carried out inan apparatus consisting of a series of units through which series themeal is moved in one direction and the solution in the other. The mealand solution in the Iorm of a relatively thick mixture or suspension isagitated in the bottom portion of each unit but slowly enough so thatsettling of solids from the settling zone into the agitation r mixingzone is permitted; `whereby clear solution overflows :from the settlingzones. The mixing zone and the settling zone, of each unit, are ratherdenitely divided, and theV thick mixture or suspension from they mixingzone of one unit moves t0 the mixing zone of the next unit, throughconnections which are below the upper levels of the mixing zones, and soon throughout the series of units, which may be multiplied in number toany desired extent. The solution, of zein in alcohol, for example, (thefresh solvent being introduced into the last of the units) overiiows oris otherwise removed, from the upper portion of each unit, as clearsolution, and is introduced into the agitation zone of the next unit inadvance in the series, countercurrent, therefore, to the movement of thesolids.

Control to isure the discharge of the ilnal solution, substantially freefrom solids and containing the required content of solubles, 'iseffected by employing a larger or a smaller number of units, byregulating the quantity of feed into the first unit,'and, if necesary,by adjusting the levels of the overflows from the units individually. A

The invention is illustrated in the accompanying drawings wherein Fig. 1is a longitudinal sectional' view of a preferred form of the apparatuswith certain parts broken away and with the pumps for transferring thesolution from unit to unit shown in dotted lines, indicating theirposition back of the extraction tanks; and

Fig. 2 is a fragmentary planview of the apparatus shown in Fig. 1.

The apparatus consists of a plurality of extraction units, the drawingsshowing four, designated A, B, C and D, respectively, the latter unitbeing the end unit, shown fragmentarily, l

from which the spent material is withdrawn and into which the freshsolvent is introduced.

The unit Aconsists of a tank I0; the bottom of which is preferablysemi-cylindrical as shown at II; and in this portion of the tank islocated a rotary agitator I2 which turns in the direction indicated bythe arrow (Fig. 1). The level oi.' the suspension,'or upper limiit ofthe agitation zones in the units A, B, and C is indicated by the dottedline a-a; the operation of the apparatus being regulated so that thereis very little agitation above this level, whereby a quiescent settlingzone is provided in which clarication of the solution takes place by thesubsidence of solids through this settling zone and into the agitationzone. Tank Ill` of unit A isprovided with a down-spout I3 (Fig. 2)intqwhich the fresh meal is fed by a conveyor Il.' lSolution from unit Bis introduced into the down-spout I3 through pipe I5, as will behereinafter described. The down-spout I3 preferably extends into, or atleast comes close to, the' mixing zone of the unit.

Any suitable means is used for withdrawing the clear liquor from theunit A, this clear liquor being the finished extract. In the drawingsthere is shown for this purpose an overow vessel I6 adjustably securedto the top member I'I oi' the apparatus (which forms a cover for all ofthe tanks) by means cf hangers I8. In this way the level at which thevsolution is discharged from the unit A may be varied for the purpose ofcontrol. The iinished solution or extract is discharged from theoverflow vessel I6 through pipe I 9.

The units B and C are constructed substantially like unit A (andcorresponding parts are given thel same designating numerals) exceptthat the pipe connections are different and the down-spouts 2li, 2l ofunits B and C are narrower than the down-spout I3, as they are intendedonly for solution and not for solid material. The down-spouts 20 and 2|,and the down-spout 22 of unit D, to be described, are preferablytransversely elongated but not to as great an extent as the transversedimensions. of the respective tanks and are in staggered arrangement asshown in Fig. 2.

'I'he adjustable overflow vessel I6 of unit B is Iconnected by pipe 23to a pump 24, from which charges through pipe 28 to a pump 29, "the,

eduction pipe 30 of which leads to the downspout 2|. The down-spouts 20and 2| are preferably carried down as far into-the agitation zones aspossible so as to insure proper 'mixing -tling zone; agitators in saidmixing zones; said mixing zones communicating one with the other throughorices at a level below the settling.

zones; means for feeding material by gravity into the mixing,` zone ofthe flrst unit of the series;

means for introducing solvent into the last unit 1 of the series toextract solubles -i'rom said material; means for discharging extractfrom the of thesolution lwith the thick mixtures in the A bottom zonesof the units.. 'I'he bottom portion I| of unit A is formed with anopening 3|, considerablyv below the level of the suspension a-a throughwhich the thick mixture in the unit `A passes into the agitation zone ofunit B. There are similar openings 32 and 33 between units B'and C and Cand D, respectively. The

`spent meal is removed from unit D by the endlessdrag chain 34 whichdischarges the material into a down-spout 35. The fresh solvent entersthe down-spout 22, of unit D, through pipe 36.

It will be observed that the operation of the apparatus may becontrolled by the rate at which the meal is fed into unit A, and therateat which the fresh solvent is delivered to the last unit D. Thesecontrols are such that the solubles may be as fully extracted from thematerial treated as may be desired, and the extract discharged from theapparatus claried to the extent desired. Further control is eiected, foreach unit individually, by the vertical adjustment yof overflow vesselsI6. The agitators I2 are rotated rapidly enough to properly the solutionwith the meal so as to insure eflicient extraction, but the movement ofthe agitators is controlled so that there will be, in each unit, abovethe agitation zone, a quiescent or settling zone through which solidsmay subside into the agitation zone, whereby a relatively clear liquor,substantially free from solids, is drawn off from the upper part of eachunit, more particularly from the upper part of 'unit A. The movement ofthe thick meal suspension from unit to unit is by gravity, the head ofliquid in -each successive unit being less than in the preceding unit.

We claim: l. Extraction apparatus consisting of a series of units, inhorizontal arrangement side by side, each comprising a tank the lowerpart of which provides a mixing zone and the upper part a setsettlingzone of each unit into the mixing zone of the next unit in advance inthe direction of the first unit, said discharge being at points tomaintain liquid levels progressively higher in thedirection of the rstunit whereby a gravity ilow of the material takes place through theapparatus; and means for removing spent material from the last unit.

2.l Extraction apparatus consisting of a series of units, in horizontalarrangement` side by side, each comprising a tank the lower part ofwhich provides a mixing zone and the upper part av settling zone;agitators in said mixing zones; said mixing zones communicating one withthe other through orifices at a level below the settling zones; 'meansfor feeding material by gravity into the mixing zone of the iirst unitof the series; means for introducing solvent into the last unit of theseries to extract solubles from said material; means for dischargingextract from the settling zone of each unit into the mixing zone of thenext unit in advance in the direction of the first unit, said dischargebeing at points to maintain liquid levels progressively higher in thedirection of the first unit whereby a gravity flow of the material takesplace through the apparatus; means for removing spent material from thelast unit; and means for adjusting the liquid levels maintained in said.units for the purpose of controuing the now of the material insuspensiod. through the apparatus.

3. Extraction process which comprises: causing a regulated gravity flowof a heavy water suspension of the material from which the extract is tobe made through the bottom portions of a series of vessels, inhorizontal arrangement side by side, from the bottom ofone directly tothe Ibottom of the next without passing through the upper portions ofthe vessels; agitating the material in the bottoms of the vessels withthe liquid there above quiescent; introducing solvent into the materialin the last of the series of ves\ sels to extract solubles from saidmaterial and withdrawing extract from the upper part of the first vesselof the series; withdrawing extract from each of the vessels, beginningwith the last, at points to maintain progressively higher liquid levelsin the vessels in the direction toward the entering material, andintroducing the ex- A tract, in each case, into the material of thenextvessel in advance; and removing the material from the last'of thevessels.

LLOYD C. SWALLEN. HAROLD REINTJES.

